1. Field of the Invention
The present invention relates to a tube support for use in a heat exchanger.
2. Description of the Related Art
Frequently, in a heat exchanger, fluid will be made to flow within a conduit along the exterior of heat exchanging tubes. The tubes must be held in place by tube supports fitted within the conduit. Two important factors influence the suitability of the tube support: it should be non-blocking of the fluid and it should allow for easy installation of the tubes despite manufacturing tolerances.
Conventional tube supports are deficient in both areas. Those tube supports are typically fashioned from parallel plates which are held together by orthogonal retaining members passing through the plates. Typically, those retaining members are located in the same plane approximately one tube diameter apart. Examples of such conventional tube supports are shown in U.S. Pat. No. 4,480,594 to Sullivan et al. and U.S. Pat. No. 4,013,024 to Kochev, Jr. et al.
The orthogonal retaining members in a conventional tube support limit the available cross section through which the heat exchanging fluid may flow. Additionally, they tend to create a high velocity which results in a large pressure drop as the fluid passes through the blocking area. This pressure drop is critical because the heat exchange fluid is often near the saturation point, and the pressure drop will cause the fluid to produce gas bubbles (i.e., flashing). Flashing further blocks the fluid flow.
Additionally, the retaining members in conventional tube supports make it difficult to insert the tubes. Since the retaining members are relatively close together, it is critical that the tube supports be closely aligned so that tubes may be installed easily. Any warping of a support makes installation difficult.